Dc Zero-Center Ammeter For Battery/Load Monitoring; High Dc Voltage Charger Shutdown With Alarm Relay - HindlePower SCR series Operating Instructions Manual

Once the system is balanced any changes in the load will be shared equally by the two chargers. If
either charger is shut down or becomes inoperative, the other will assume the total load up to the point
where its current limit circuit operates. It is possible to operate each charger independently by setting
switch SW10 (LOAD SHARE) to the OFF position.
12. DC ZERO-CENTER AMMETER FOR BATTERY LOAD MONITORING (EJ0138)
Purpose and Description: The zero-center ammeter is in the negative return lead of the battery. It
indicates the direction and amount of the battery current. Indication on the meter is to the right of center
when the charger is charging the battery and to the left when the battery is furnishing current to the load
(discharging).
13. HIGH DC VOLTAGE CHARGER SHUTDOWN WITH ALARM RELAY & LIGHT (EJ0592)
Purpose: The High Voltage DC Shutdown functionally disables and locks-out the battery charger
whenever the output DC voltage exceeds the preset upper limit of charging voltage. This option is
designed to protect the batteries and/or load from an over-charger or over-voltage condition. In the case of
parallel, redundant chargers with charger shutdown, this option selectively detects and shuts down the
faulty charger/rectifier only. The option provides a front panel indicating light and alarm contacts wired to
TB3 terminals 53, 54, 55.
Description: The high DC voltage detector PC Board assembly, A13, is an HVA alarm module which
closes a circuit on alarm and energizes the shutdown relay K21. The shutdown relay disconnects the A1
control module from its AC supply thus removing the SCR trigger signals to the rectifier. This disables the
charger and output current goes to zero. After shutdown the circuit must be manually reset before
restarting the charger. A "CHARGER RESET" momentary switch, SW14, is provided on the front panel
for this purpose. The high DC voltage detector circuit has a built-in, several second, time delay to prevent
charger shutdown due to transient voltage surges.
Adjustment for the shutdown circuit is provided by potentiometer R4 on the A13 assembly. It can be
field adjusted using the same adjustment procedure as for the HVA portion of the EJ0083 option on page
14.
The factory preset thresholds for charger shutdown are as follows unless otherwise specified:
2.40 volts/cell for LEAD ACID
1.65 volts/cell for NICKEL CADMIUM
NOTE: The above set points are the same as the High DC Voltage Alarm (HVA). If an HVA and
High Voltage Shutdown are ordered on the same charger, the shutdown thresholds are set
as follows unless otherwise specified:
2.45 volts/cell for LEAD ACID
1.70 volts/cell for NICKEL CADMIUM
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